Electrolytic condenser



May 26, 1936. A. E. VAN ARKEL ET AL 2, 2,283

ELECTROLYTIC CONDENSER Filed March 22, 1933 2 Sheets-Sheet I M mm n R AN ON R MW J 0 E H A mam B y 1936- A. E. VAN ARKEL ET AL 2,042,233

ELECTROLYT I C CONDENSER Filed March 22 1933 2 Sheets-$heet 2IIIINVENTORS ANTON E, VAN ARKEL HENDRIC Jg EMBDEN E, M

' ATTORNEY I Patented May 26, 1936 PATENT OFFICE ELECTROLYTIC CONDENSER.i

Anton Eduard van Arkel and Hendrik Johannes Meerkamp van Embden,Eindhoven, Netherlands, assignors to Radio Corporation, of

America, a corporation of Delaware Application March 22,

1933, Serial No. 662,114

In Germany March 9, 1932 3 Claims.

This invention relates to improvements in an electrolytic condenser.Such a condenser comprises an .electrode consisting of a metal which iscoated with a layer consisting of a compound of the metal, in general,an oxide, this layer constituting the dielectric. The other electrode isconstituted by the electrolyte which is provided with a supply conductorfor which may serve the wall of the vessel containing the condenser ifthis vessel consists of a metal. If the condenser s not only used forsmoothening direct current, but also for alternating current, twoelectrodes furnishedwith an oxide layer must be immersed into theelectrolyte.

The present invention has for its purpose to lodge a condenser surfacewhich is as large as possible in a small volume and to use, in spitethereof an electrode-form which may be obtained in a simple manner.

This is realized owing to the fact that at least one electrode isconstituted by a rod which is provided with a profile extendingin alongitudinal direction of the rod.

volume it has already been proposed to turn grooves in a cylinder, whichgrooves extend practically at right angles to the longitudinal directionof the cylinder. However, the manufacture of such an electrode is veryexpensive. Furthermore, it has already been suggested to compress acylinder, thus forming folds extending in a transverse direction. Thishas the draw-back, however, that the arrangement of the electrode isattended with diificulties.

The electrode according to the invention on the contrary may beestablished very cheaply by mass production. For this purpose theelectrode is so shaped that the cross section at right angles to thelongitudinal direction is equalthroughout, so that it is possible toestablish the electrode by squirting (pressing) or drawing.

It is not necessary to connect such a rod to the fastening parts byriveting, welding or in some other way, since in a suitable form ofconstruc.- tion the profile may be removed, preferably by turning, frompart of the electrode, thus obtaining a smooth surface, and this partmay be passed through the cover of the condenser.

In this manner a very simple arrangement is obtained. Moreover, it isvery advantageous for the working of the condenser that the electrode ismade in one piece and is not provided with riveted joints, since suchjoints give rise frequently to breakdowns.

In order to lodge a large surface in a small The invention will be moreclearly understood by reference to the accompanying drawings,representing, by way of example, some forms of construction thereof.

Fig. 1 shows a form of construction of an electrode according to theinvention.

Fig. 2 is a section of a condenser comprising such an electrode.

Figs. 3-6 are detail views of forms of construction in which separatefastening or terminal parts of the electrodes are provided, and in whichthe point of attachment is separated from the interior of the vesselcontaining the condenser.

Fig. 7 is a cross section of an electrode having a different profile.

Fig. 1 shows that the electrode l has a star shaped cross section, thusobtaining a very rigid electrode having a large surface. The upper partof the electrode is turned off, thus obtaining at this point a discshaped part 2 and a terminal stud 3, which latter is provided with a.screw thread 4. In Fig. 2 the electrode I is immersed into anelectrolyte contained in the condenser vessel 6. The pin 3is takenthrough the cover I of the condenser and is pressed against the screwedpart 4 by means of a nut 8. With the aid of the rubber ring 9 providedbetween the disc-shaped part 2 and the cover 1 a perfect obturation isensured. Though in this form of construction the electrode passesthrough the upper part of the vessel, such condensers are usuallyarranged upside down so that the cover 4 is positioned in the bottom ofthe container. In this case the electrode I is completely immersed intothe electrolyte.

' Fig. 3 shows a part of an electrode which is eouipped with a largenumber of fins. Also in this case the upper part is turned off so as toform a disc 2. At the middle is provided a screw threaded bore ill asappears from the corresponding section of Fig. 4, in which a specialmanner of attachment to the cover H is indicated. Into the aperture I0is screwed a terminal stud l2 passing through an aperture in the cover Hand being provided with a nut I3. By means of the nut the upper surfaceof the disc 2 is pressed against a rubber ring l4 forming the obturationbetween the disc 2 and the cover II. If the condenser, which is partlyshown in Fig. 4, is placed upside down and a suflicient quantity of someelectrolyte is introduced into the vessel, the whole electrode togetherwith the disc 2 is immersed into the electrolyte. However, the jointbetween the electrode l and the stud bolt does not contact with theelectrolyte.

Figs. 5 and 6 show diagrammatically and in section respectively a detailof a form of construction with which the same result is obtained. Theelectrode has a conical upper end I5 and is drawn in a correspondingbore of the cover M .by means of the stud bolt l2 and the nut l 3, thecone l5 per se constituting a suflicient obturation.

Fig. 7 is a section of an electrode whose fins are corrugated so as toincrease the surface.

It will be appreciated that the profiles illustrated constitute forms ofconstruction which may be obtained by drawing or by squirting (pressing)a material through an aperture having such a profile.

Many other profiles are possible and the grooves need not exactly extendin the longitudinal direction of the rod, since they may also form aweak wave line or a screw having a very large pitch.

Furthermore, the fins of the profile shown in the drawing may beprovided with special profiles also extending in a longitudinaldirection.

In certain circumstances the rod may also be bent.

We claim: a

1. An electrolytic condenser comprising a metallic container whichserves also as one electrode,

an insulated cover for said container, 2. central aperture in saidcover, a one piece central electrode having a plurality of corrugatedradial fins extending out from the central portion of said electrode, athreaded aperture in said central electrode, an upward extendingterminal stud secured in the aperture of said central electrode andpassing through the aperture in said cover and mechanically securedthereto.

2. An electrolytic condenser comprising a metallic container whichserves also as one electrode, an insulated cover for said container, anelectrolyte partly filling said container, 2. central aperture in saidcover, a one piece central electrode having a plurality of corrugatedradial fins extending out from the central portion of said electrode, athreaded aperture in said central electrode, an upward extendingterminal stud secured in the aperture of said central electrode, thejunction point of said terminal stud and said electrode being locatedabove the top level of said electrolyte.

3. An electrolytic condenser comprising a me tallic container whichserves also as one electrode, an insulated cover for said container, anelectrolyte partly filling said container, a central aperture in saidcover, a one piece central electrode having a' plurality of corrugatedradial fins extending out from the central portion of said electrode, athreaded aperture in said central electrode, an upward extendingterminal stud secured in the aperture of said central electrode andpassing through the aperture in said cover and mechanically securedthereto, the junction point of said terminal stud being located abovethe top level of said electrolyte.

ANTON EDUARD VAN ARKEL.

HENDRIK J OHANNES MEER- KAMl? VAN EMBDEN.

